Immunological activities of Ginseng Radix water extract (GE) were compared with theirs of Insamhodo-tang water extract (IHT). GE and IHT (500 mg/kg) were administered p.o. twice a day for 5 days to C57BL/6 mice, respectively. IHT decreased the cell viability of murine thymocytes and splenocytes, but increased the population of $CD4^+$ cells in thymocytes, and the population of $Thy1^+$ cells and $CD4^+$ cells in splenocytes in contrast to GE. In addition, IHT decreased the phagocytic activity of peritoneal macrophages, but increased the production of nitric oxide from peritoneal macrophages in contrast to GE. These results suggest that IHT decrease a specific- and nonspecific immune reaction in comparison with GE.